Function assign

packages/core/src/actions/assign.ts:138–186

(
  assignment:
    | Assigner<LowInfer<TContext>, TExpressionEvent, TParams, TEvent, TActor>
    | PropertyAssigner<
        LowInfer<TContext>,
        TExpressionEvent,
        TParams,
        TEvent,
        TActor
      >
)

 *   update.
 */
export function assign<
  TContext extends MachineContext,
  TExpressionEvent extends AnyEventObject, // TODO: consider using a stricter `EventObject` here
  TParams extends ParameterizedObject['params'] | undefined,
  TEvent extends EventObject,
  TActor extends ProvidedActor
>(
  assignment:
    | Assigner<LowInfer<TContext>, TExpressionEvent, TParams, TEvent, TActor>
    | PropertyAssigner<
        LowInfer<TContext>,
        TExpressionEvent,
        TParams,
        TEvent,
        TActor
      >
): ActionFunction<
  TContext,
  TExpressionEvent,
  TEvent,
  TParams,
  TActor,
  never,
  never,
  never,
  never
> {
  if (isDevelopment && executingCustomAction) {
    console.warn(
      'Custom actions should not call `assign()` directly, as it is not imperative. See https://stately.ai/docs/actions#built-in-actions for more details.'
    );
  }

  function assign(
    _args: ActionArgs<TContext, TExpressionEvent, TEvent>,
    _params: TParams
  ) {
    if (isDevelopment) {
      throw new Error(`This isn't supposed to be called`);
    }
  }

  assign.type = 'xstate.assign';
  assign.assignment = assignment;

  assign.resolve = resolveAssign;

  return assign;
}